Fluid gear.



B. C. SHIPMAN. FLUID GEAR. APPLLCATION FILED JAN. IBI JBM- Patented July 3,1917.

W/fnesses l'nveafor .55 the driving member stores noenergy l 40 and the gear ratio will be unity,

I UNITED STATES PATENT OFFICE.

BENNET CARROLL SHIPMAN, OF SAN FRANIJISCO, CALIFORNIA.

" FLUID GEAR.

To all whom-it may concern:

lie it known that I, llnNNi-rr CARROLL .SlurMAN, a citizen oi the United States, residing athan Francisco, in the county of 5 San l raneisco and State of California, have invented certain new and useful Improve merits in l luid (tears, of which the follow- .ing is a specification.

My invention has for its object the pro- LO dllt'il'lllll'Of a gear by which any ratios ol speeds can be secured between a driving and driven shaft with a corresponding change of torque.

lloretolore all devices for mechanically 5. changing speeds have labored under one of two objections. either they give only certain definite ratios of speed change with correspondingly inversely proportional torques. ol"-whi '.h lathe gearing: is the type. or they ZO-give. indefinite ratios of speed change. hut on'ly one torque. oi which the friction change. gear is the. type. A satisfactory gear must give. both an indefinite ratio of speed changes auu'at the same time give. a torque inversely .25 proportional to the speed change.

"My invention aecomplishes this result by utilizing. the inertia of a moving: mass attached to the driving member storing energy llp'oughonlpart oi its motion. and trans- -Ilerring it to the driven memher thrv'iugh another part ol its motion. thus iucreasigng the intensity of motion transmitted. and eon respoudingly diminishing thev amount of l lfi" -tion imparted. It ,will be evident that lil {It delivers it eontiniiiously at an times to the driven memher. there will he. no gear action as the torque. from the, driver to the driven member will be, the same and therefore ci'p Ll, in otier words the speeds will be the same. ll? however the driving member stores energy due lug: one-half of its movement, and delivers hoth its stored energy audits normal energy during the. second hall of its movement the intensity of such delivery will he double its normal. in other words the torque will be twice. but the motion imparted will he one.- hall. the.; -haraeteristies ol :1 true gear. 5otalso if the period were taken as one-quarter or threc-quarters or any other 17 notional periodn "lhus I ran. make any gear ratio desired lroinunity lo iulinity and y a uniform gra'dualion. v

The means ol'accomplishing: this result are essentially a driving shalt carrying a Specification of Letters Patent.

Application filed January 13, 1915.

'lo the pump.

Patent-ed July 3. 1 91 '7.

Serial No. 2,039.

suitable fly wheel, a pump driven thereby, adapted -to deliver a fluid through a check valve to a fluid-operated motor attached to the driven shal't the discharge of which motor alter passing:- through a throttle valve returns to the pump as a suction. In the discharge-suchon pipe should be a storage chamber sullicienlly large to aeconnuodate the contents of the pump and in certain cases. when desired, of the. motor also. With the throttle valve wide open. the fluid will eireulale lreely in the closed system. and with pump and motor ol'i equal capacity, the driving and driven speeds will be the same, the lly wheel in this case performing: no function. 'l'l' the throttle valve be partially closed. so I Hit the. pump is able. to draw but a portion of its capacity. a correspomlingly inverse portion of its operation will be on vacuum and therefore without load. the ex .eess energy of the shaltliving. absorbed by the fly wheel- As the pump draws only a portion of its capacity it delivers only the Same amount to the motor. henee the motor" must run at a rtalueed speed, but at a greater torque hy the added amount of the stored energy ol the fly wheel superimposed on the normal energy oi the driving shaft. both delivered to the pump in its correspondingly shortened period of working.

Figure 'l is the simple form oi my invention, showing;- the essential elei'nents in plan. Fig. 3 is a more elahorate modification in side elevation. showing a means of cutting out the fluid apparatus. when the ratio is unity. Fig. 3 shows an application of the invention to a plurality of motors.

Descrihin; my invention in detail, Fig. 1 shows a simple "form in which 1. is a driviue' shaft. 3. a fly wheel on same. 3. any suitable pump attached by any means to said shaft. in this case a rotary pump, 4. a check valve. at the delivery of said pump, 5. a. discharge line from pump to motor. 6. a

suitable motor operatahle by lluid under pressure. in this case a rotary motor similar suction of the pump. 8, storage ohamher connected to the said exhaust line. 9. a throttle val ve for regulating the amount of fluid allowed to reach the pump. 10. a driven shaft attached. by any suitahle means to the afore said fluid motor.

If it be. assumed that a load is thrown on the driven shaft. which cannot be pulled by the said shaft at some given speed and 7. an exhaust line hack to the.

torque, it will be evident that by throttling, the amount of fluid admitted to the pump can be reduced to such a point that it will cause the motor to run at some lower speed, at which the load can be pulled if the torque has risen in proportion to the reduction in speed. The torque will. so rise, for the rea son that, if throttled, the pump during part of the revolution is delivering no energy to the fluid and thence to the motor, but such energy is being stored in the fly wheel, while during that portion of the revolution when the pump is delivering energy to the fluid and thence to the motor, the energy of the fly wheel is being delivered up again and added to the constant energy of the driving shaft, thus increasing the pressure of delivery from the pump which in turn causes a greater torque on the motor. The above variation of speed and torque can be effected down until the speed of the driven shaft reaches zero, when the throttle valve will be entirely closed, the pump working on a vacuum,-and therefore consuming no power except for internal friction, while the motor and fluid are at rest, and the amount of fluid normally required to fill the pump is in a direct the storage chamber, 8.

Fig. 2 shows a modification of my inven- ,tion, in which provision is made for using drive when the gear ratio is unity, thus cutting out of operation the pump and motor, when it is desired to realize the maximum efliciency for periods of long runs.

The same numbers refer to similar parts, and in addition the following; 11, a quill to which the operating member of the pump is connected, the driving shaft, 1, passing through such quill. ()n the end of the quill next to the driving and is attached the fixed clutch member of the clutch, 12, the movable member being slidably attached to the driving shaft, 1, in the wellunderstood manner of jaw clutches. The operating member of the fluid motor is likewise connected to a quill, 14, through which the driven shaft, 10, extends and tern'iinatcs in close proximity to the driving shaft, 1. 0n the driving shaft, 1, and on the quill, 14, of the motor are a ttaehed two fixed clutch members of the double acting clutch, 13, so arranged that the movable member of said clutch, mounted slidably on the driven shaft, 10, may engage alternately either fixed clutch member, in a well understood manner. The sliding memhers of both clutches are controlled by shifting mechanism, 15. so arranged that both said members {.ravel in unison and in the same direction.

in starting operation, as shown, the shifting lever would be in such position that the clutch, 12, connects the driving shaft with the quill of the pump and the clutch, 13, connects the driven sl'iaft with the uill of the motor. When the throttle is wi e open and .both shafts are turning at the same speed, a movement of the shlftii g lever in the direction of the driving sha t will disengage the driving shaft from the quill of the pump and engage the driving shaft with the driven shaft directly, at the same time disengaging the driven shaft from the quill of the motor. In this way the drive will be straight through, and the pump and motor will be idle, thus economizing the internal losses of that apparatus and ,the fluid.

The rotary valveless type of pump or motor. a number of which are on the market and are well understood, is indicated and therefore details of such apparatus are not shown, forming no part of this invention. This type of apparatus lends itself particularly to this form of construction, but I do not limit myself to such types. Any suitable pump and motor could be substituted without departing from the spirit of my invention.

it is evident that the pump could drive more than one motor if desired, and at any desired speeds, by simply attaching such motors in a similar manner to the one shown, and making their capacities in inverse proportion to the speeds desired, for a given pump speed. Thus a' change gear can be built to control more than one driven shaft, and at the same time allow a variation in speeds between the driven shafts. as for instance in the rear wheels of an automobile. Such an arrangement would not only provide a change gear, but also a differential gear.

llaving described my invention, I desire to secure by Letters Patent, and claim:

1. A speed changing mechanism comprising a driving shaft, 8. moving, mass of relatively large inertia. connected thereto, a fluid pump driven thereby, a check valve in the discharge of said pump, a fluid motor connected to said discharge and to a driven shaft, the exhaust of said motor connected to the suction of said pump, a storage chamber connected to said exhaust, and a regulating valve interposed in said suction petween the pump and said storage chain- 'ier.

2. A speed changing mechanism comprising, a driving shaft, a mass of relatively large inertia mounted thereon, a positive displacement fluid pump connected thereto, a supply of suitable fluid, a check valve in the discharge of said pump, a positive displacement fluid motor connected to'said discharge and attached to a driven shaft, the exhaust from said motor connected to the. suction of said pump, a storage chamber connected to \the said exhaust, and a.

valve adapted to regulate the supply of fluid to the suction of the pump. 3. A hydraulic gear comprisin a drivmg shaft, a flywheel mounted t ereon, a

positive displacement pump connected thereto, a ositive displacement motor connected to a riven shaft, a supply of liquid, a connectionv from the discharge outlet of the said pump to the admission inlet of said motor, a check valve in said connection, a connection from the exhaust outlet of said motor back to the suction inlet of said pump, a storage chamber connected there to and. a valve therein between said storage chamber and said suction inlet adapted to regulate the amount of liquid. admitted to such suction inlet.

4. A. hydraulic gear comprising a driving shaft, a flywheel thereon, a rotary positive clis ilacemcnt pump connected thereto, a rotary positive displacement liquid motor connected to a driven shaft, a connection I, from the discharge of said pump to the ad-' missioninlet of said motor, a checkvalve in said discharge connection, a connection from the exhaust outlet of said. motor to the suction inlet of said pump, a. storage chamher connected thereto, avalve connected therein between said, storage chamber and said suctlo-n inlet, adapted to control the amount of liquid. admitted to such suction .inlet, and supply of suitable liquid sufii cient to fill the pump, motor, and connecting lines. o

5. A hydraulic gear comprising driv- .ing shaft, flywheel connected thereto, fluid pump driven thereby, a connection. from the discharg-i of said pump to the mission ports of one or more fillld motors, a

check valve in the discharge of said pump, a connection from the exhaust of said motor or motors to the suction inlet of said pump, a storage chamber connected thereto, and a valve controlling the suction of said pump.

6. A speed changing mechanism COIIIPIlS ing a driving shaft, a flywheel connected thereto, clutch thereon ada ted in one po' sition to engage a quill tiereon, a fluid pump opcratively connected to said quill, a driven shaft, a clutch thereon adapted in one position to engage a quill thereon andin another position to engage the said drivin-g shaft direct, a fluid motor operatively connected to said quill on driven shaft, a fluid connection between discharge of said pump and admission port of said motor having a check valve therein, a fluid con nection between exhaust port'of said motor and suction of said pump, having a storage chamber connected thereto, and a regulating valve therein, with means for operating clutches simultaneously.

7. A fluid gear comprising a pump, a check valve, a fluid motor, a receiving chamber, and a throttle valve, connected in a" closedcircuit in the order named, the pump being mechanically connected to a driving shaft, and a flywheel, and the motor beingmecl'umically connected to a driven shaft.

BENNET lARROLL SHIPMAN.

"W. is:

V. Hons, Flinn Fiona. 

